Filter dryer unit for cleaning sealed refrigerating systems after motor burn outs



March 30, 1965 5, BALOGH 3,175,342

FILTER DRYER UNIT FOR CLEANING SEALED REFRIGERATING 2 Sheets-Sheet 1 SYSTEMS AFTER MOTOR BURN OUTS Filed Jan. 16, 1963 INVENTOR STEPHEN BALOGH March 30, 1965 s. BALOGH 3,175,342

FILTER DRYER UNIT FOR CLEANING SEALED REFRIGERATING SYSTEMS AFTER MOTOR BURN OUTS Filed Jan. 16, 1963 2 Sheets-Sheet 2 I0 P, m

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GO D 0 O O O INVENTOR l STEPHEN BALOGH United States Patent 3,175,342 FlLTER DRYER UNIT FUR CLEANKNG SEALED REFRIGERATING SYSTEMS AFTER MOTOR B OUTS Stephen Balogh, Lyons, N.Y., assignor, by mesne assignments, to Parker-Hannifin Corporation, Cleveland, ()hio, a corporation of Ohio Filed Jan. 16, 1963, Ser. No. 251,804

4 Claims. (Cl. 55-316) This invention relates to a method, apparatus and filter dryer unit for cleaning sealed refrigerating systems after motor burn outs.

Generally there is provided a relatively large combined filter, dryer and acid remover adapted for temporary insertion into the suction line of a refrigerating systern. The general construction of the filter and dryer unit is similar to that of the permanently installed unit disclosed in applicants prior application entitled Ceramic Block Filter Dryer, Serial No. 214,663, jointly filed by applicant and Ronald M. Wilber on August 3, 1962.

The filter, dryer and acid absorber unit comprises an elongated cylindrical shell the outlet end of which is filled by a filter block molded of ceramic material and closed at-one end by an integral wall. The cavity in the block is bridged by a fine meshed screen supported on a perforated plate. Most of the remaining space within the shell is filled with loose type desiccants and acid absorbers, such as molecular sieve, activated alumina and silica gel, gently compressed axially within the shell by a pair of annular elements transversely bridged by fine meshed strainers.

When the motor of a sealed motor and compressor unit has burned out, the same is replaced along with the usual permanently installed filter and dryer unit, after the system has first been drained and flushed. A clean up filter and dryer unit is then installed in the suction line immediately before the compressor. Next, the sys tern is charged with refrigerant and operated under (nearly) normal conditions for at least three days. The clean up unit is then removed and a bypassing jumper is substituted therefor in the now fully renovated system.

Cleaning up of a refrigeration or air conditioning system after a motor burn out is one of the most ditficult jobs for the service man. There are various methods used in cleaning a system recommended by refrigerant manufacturers which are excellent if carried out properly, but there is too much left to guess work on the service mans part. The use of a refrigerant to flush out a system usually removes only those large particles of residue which are relatively free in the lines. A major portion of the residue left in the system usually is composed of tiny particles of sludges, etc., which cling to the tubing surfaces and are removed only after a longer period, usually of 48 hours duration under actual operating conditions.

It is accordingly an object of the present invention to provide a combined filter, dryer and acid absorber unit especially designed for temporary installation in a refrigeration system for cleaning the same after a motor burn out.

It is another object of the invention to provide such a unit which is of simple, inexpensive yet highly effective design.

It is a further object of the invention to provide a novel and highly etlicient method for renovating a refrigeration system after a motor burn out.

It is yet another object of this invention to provide a simple means for facilitating the insertion and removal of the herein disclosed unit from a refrigeration system.

Other and further objects of the invention will become 3,175,342 Patented Mar. 30, 1965' apparent from a reading of the following specification taken in conjunction with the drawings, in which:

FIGURE 1 is a plan view, partly in axial section, of a preferred embodiment of the combined filter, dryer and acid absorber unit,

FIGURE 2 is a plan view, partly in axial section, of a modified form of unit,

FIGURE 3 is a schematic diagram of a system utilizing one of the units during renovation of the system, and

FIGURE 4 is a fragmentary schematic diagram showing a modified form of the unit coupling portion of the system.

With reference now to FIGURE 1 of the drawings, the numeral It generally designates a preferred embodiment of a unit according to the present invention. The unit ltl comprises a cylindrical case formed of a pair of axially aligned cup shaped metallic shells 11 and 12., the abutted rims of which are herein disclosed as being joined and hermetically sealed by a close fitting band 13 welded or soldered thereto. However, the case 1142 can be formed in numerous other manners and the parts joined after the filtering and renovating parts and materials are placed therein. The case Til-l2 may have a length of approximately seven inches and a diameter of about an inch and a half for use with refrigerating systems of from two to five tons capacity.

The ends of the shells 11 and 12 are provided with tubular coupler sleeves 1 soldered, brazed or welded coaxially thereto. The shell 11 constitutes the intake portion of the unit it) and is substantially filled with granular or other loose desiccant and acid absorbing and/or neutralizing material or materials, such as molecular sieve, activated alumina and/ or silica gel. The desiccant material, designated 15, is loosely compressed and held between a screen assembly 16 and a cup shaped perforated bafile 17 the flanged rims of which are press fitted into the shell 11.

The screen assembly 16 has a double folded marginal flange, the folds of which embrace and firmly anchor a marginal flange on a disc strainer 18 formed of mesh Monel Woven screen.

The outlet end of the shell 12 is bridged by another perforated cup shaped battle 19 against the downstream side of which a mesh Monel Woven screen 2b i held by the inturned flange of an annular element 21.

A conically tapered filter block 22 of porous porcelain has its larger end snugly seated in the cup shaped baffle 19. A compressed coil spring 23 maintains desired positions of and spacing between parts 17 and 22. The filter block 22 has a cavity 24 in one end to increase the filter area, and a depression 25 in its other end for the same purpose and also for providing a centering seat for the apex of the conically coiled spring 23.

The unit of FIG. 2 is generally designated 26 and comprises a pair of aligned cup-shaped shells 27 and 28 joined by a band 29. The unit 26 has a length of about twelve inches and a diameter of the order of two inches, being designed for use with systems of from five to ten tons capacity.

Granular desiccant 36 is loosely held in the shell 27 between two strainer discs 31 of 100 mesh Monel woven screen, the marginal flanges of which are clamped between the double folded marginal flanges of a pair of annular elements 32. The shell 2% has press fitted therein an annular element 33 and a perforated cup shaped baffle 34, between which is clamped and held a strainer disc 35 of 150 mesh woven Monel screen.

A conically tapered porous porcelain filter block 36 is coaxially held in the cup shaped bafile 34 by a coil spring 37 compressed between the screen assembly 31-32 and a coarse screen support disc 38. The filter core block 36 is 3 similar in shape and function to the block 22 of FF- URE 1. The shells 27 and 28 have couplers 39 similar to couplers 14 of the first described species.

FIGURE 3 is a schematic diagram of a typical refrigeration system showing one arrangement for installing and removing a renovating unit according to the present invention. The numeral 40 designates the renovating unit which is inserted in a suction or low pressure line 41 connecting an evaporator 42 to a replaced combined motor and compressor unit 43. A conventional new permanently installed filter and dryer unit 44 is shown in a high pressure line 45 between the compressor 43 and a conventional condenser 45. An expansion valve 47 completes the basic refrigeration system. When the system has been cleaned (after several days of near normal operation) the unit 40 is removed and the gap in the line 41 thus formed is closed in known manner by a jumper tube 48.

In the modified installation arrangement of FIG- URE 4, a renovating unit 49 is inserted in a low pressure line 50, and a pair of manual valves 51 in said line at each end of the unit 49 is provided to isolate or to permit removal of the unit 49. A bypass branch line 52 bridges the unit 49 and its isolating valves 51, as shown, joining the line 50 at Te 53. The bypass line 52 has a valve 54 which is manually closed during the renovating period.

The herein disclosed method of renovating a refrigeration system after a motor burn out comprises the following steps:

(1) Discharge the system refrigerant to outside ambient in the liquid phase, avoiding bodily contact with refrigerant or oil, as acid burns can result from contact with sludge from burned out compressor.

(2) Remove defective compressor.

(3) Remove and discard the old high side dryer and/ or filter.

(4) Clean the expansion valve strainer and the internal expansion valve parts. Connect system Without expansion valve in system.

(5 Flush the system with new refrigerant.

(6) Reinstall cleaned expansion valve.

(7) Install liquid line dryer, using one size larger than normal selection size.

(8) Install new compressor.

(9) Install motor burn out clean up dryer in suction lines.

(10) Evacuate the entire system with a good vacuum pump.

(11) Break the vacuum with refrigerant; re-evacuate and charge the system.

(12) After at least three days, change the liquid line dryer and remove and discard the motor burn out clean up dryer. Advise the customer that reduced performance can be expected during the three day clean up period as the motor burn out dryer will introduce a pressure drop in the suction line while it is doing its work.

(13) Use jumper tube to replace void space (or turn valves of bypass system).

(14) Resume operation of the system as a completely renovated system.

For example, the case 11-12 could be of one piece construction spun on both ends after filling. Also the filter block could be a core molded of molecular sieve to absorb the water and acids that may pass through the silica gel bed. The molecular sieve is preferably but not necessarily synthetic zeolite.

What is claimed is: v

1. A combined filter, dryer and acid absorbed unit, comprising: an elongated tubular casing having inlet and outlet fixtures adjacent opposite ends thereof, a porous filter block spanning said casing adjacent one end thereof, a mass of loose fill moisture and acid absorbing material in the other end of said casing, apair of perforate disc members engaging opposite ends of said mass of material to prevent axial displacement of said material by axial flow of refrigerant through said unit, and a coil spring compressed between an end of said filter block and the adjacent disc member.

2. Structure according to claim 1, said filter block having a relatively shallow axial depression constituting a locating seat for one end of said coil spring.

3. A combined filter, dryer and acid absorber unit, comprising: an elongated tubular casing having inlet and outlet fixtures adjacent opposite ends thereof, a porous filter block spanning said casing adjacent one end thereof, a mass of loose fill moisture and acid absorbing material in the other end of said casing, a pair of perforate disc members engaging opposite ends of said mass of material to prevent axial displacement of said material by axial fiow of refrigerant through said unit, a supporting and centering disc for said filter block having a convex central portion, said filter block having a depression matingly receiving said convex central portion, and a coil spring compressed between said last mentioned disc and an adjacent disc member for urging the latter member and said filter block toward opposite ends of said casing.

4. A combined filter, dryer and acid absorber unit, comprising: an elongated tubular casing having inlet and outlet fixtures adjacent opposite ends thereof, a porous filter block spanning said casing adjacent one end thereof, a mass of loose fill moisture and acid absorbing material in the other end of said casing, a pair of perforate disc members engaging opposite ends of said mass of material to prevent axial displacement of said material by axial flow of refrigerant through said unit, said porous filter block being molded of molecular sieve, and said loose fill material being primarily silica gel.

References Cited in the file of this patent UNITED STATES PATENTS 2,283,989 Henry May 26, 1942 2,325,657 Burkness Aug. 3, 1943 2,341,430 Elsey Feb. 8, 1944 2,600,435 Shapiro June 17, 1952 2,705,405 Uhlman Apr. 5, 1955 2,873,856 Jones Feb. 17, 1959 FOREIGN PATENTS 603,135 Canada Aug. 9, 1960 OTHER REFERENCES Modern Refrigeration and Air Conditioning, Althouse et 211., published by The Goodheart-Willcox Company, Incorporated (Chicago), 1956, pages 384-389, 393, 3 96499 and 500-501 relied on. i 

1. A COMBINED FILTER, DRYER AND ACID ABSORBED UNIT, COMPRISING: AN ELONGATEED TUBULAR CASING HAVING INLET AND OUTLET FIXTURES ADJACENT OPPOSITE ENDS THEREOF, A POROUS FILTER BLOCK SPANNING SAID CASING ADJACENT ONE END THEREOF, A MASS OF LOOSE FILL MOISTURE AND ACID ABSORBING MATERIAL IN THE OTHER END OF SAID CASING, A PAIR OF PERFORATE DISC MEMBERS ENGAGING OPPOSITE ENDS OF SAID MASS OF MATERIAL TO PREVENT AXIAL DISPLACEMENT OF SAID MATERIAL BY AXIAL FLOW OF REFRIGERANT THROUGH SAID UNIT, AND A COIL SPRING COMPRESSED BETWEEN AN END OF SAID FILTER BLOCK AND THE ADJACENT DISC MEMBER. 